When my mum's friend had a baby it made me think about being an only child for the first time. I thought, would I like brothers and sisters? But to be honest, my friend's sister looked quite a hassle - he was always having to watch her. I thought, I'm better off on my own - especially as brothers and sisters seem to fight a lot, that's something I've noticed.

There are other good things, too. I get my privacy, and I like that: some of my friends have to share a bedroom and I know that will never happen to me. And there's no one to mess my stuff up, either. Plus I get time on my own with Mum and Dad, and that's special.

One thing I am pleased about is that my friend Thomas lives really close by, so it's easy for me to go and play with him. When I grow up I'd be happy to have just one child, but I'd always make sure we lived close to other kids.

Zoe Spencer-Silver, 15

One of the bad things about being an only child is the reaction you get from other people. They think you're spoilt - you see that look in their eyes. And then you have to prove you're not spoilt, although you know you're not and nor are most only children.

When I was little my friends thought I was lucky being an only one, but now when I tell friends I can tell they're thinking, that must be hard ... She's not got a sister to go shopping with, or a brother to help with her homework. All my friends have brothers and sisters. It can be a bit lonely - like when your parents go out and you're on your own with no one to talk to. I spend a lot of time chatting to my friends on the phone, and going on MSN. And I like it when one of my grannies comes over when my parents are out, because then I've got someone to talk to. I suppose, in general, I think there are more negatives than positives, but on the other hand it's all I've known and I'm OK with it.

Sarah Lee, 29

I went to boarding school when I was seven, and the hardest thing I found was making friends. Because I was an only child, I just didn't know how to do it. The thing is that when you're an only child you spend a lot of your time with grown-ups, you're not in a very child-centric home and you're often the only child in a gathering of adults. You're more of an appendage to your parents' lives than central to it: they can go on living more or less the sort of life they've always lived, only now you tag along too.

I found being an only child interesting, in that it gave me a place at the grown-ups' table and gave me a view into their world that children in a big family might not get. And I know it has, at least partly, moulded me into the person I am: I never like the idea of being one of a group, for example. If I'm pulled into a group I'm much more likely to go off and do something on my own, or with just one other person - I'm not comfortable with being one of a gang.

My parents are divorced now and my mother lives in the US and my father in the UK. I do feel very responsible for them - I feel responsible for their happiness, in a funny kind of way. I'm the closest relative in the world to each of them, and I am very aware of that.

Lorraine Mason, 36

I was a happy child: I had the undivided love and attention of two people, and it made me very confident and secure. I know some only children feel stifled by their parents, but that wasn't my experience. I found it enriching, which I think is mainly because we get on so well.

Because my childhood was happy, my instinct was to replicate it in my own family, and have just one child myself. I might have done that, but then a few years ago a close friend, who like me was an only child, was killed in an accident. It was devastating for all of us, but of course especially for his parents. It's a double blow for parents when they lose an only child: firstly because they were so close, and secondly because there's no one to go on for.

I came away from the funeral knowing I could never survive what that couple were going through, and it made me decide to have more than one child. My eldest daughter is four and a half, and my second child is 12 weeks old. I suppose the big age gap reflects the fact that I wanted to give my elder daughter that "only child" experience for as long as possible.

I do find having two children scary. The problem is I've absolutely no experience of this kind of situation: nothing in my past has prepared me for having to divide myself between the needs of these two little people, and the guilt is hard when I feel I've not been there enough for one of them. And on a practical level, things like sibling rivalry are going to be a whole new ball game.

Ann Richardson, 49

I always felt a little odd, and assumed it was something about me. It was only in my 30s, when I was training to be a psychotherapist, that I found myself with a group of only children, describing our experiences. It was a revelation because it made me realise that other people felt many of the same things.

Growing up in a small unit means the experience is intense, so we can be rather intense, especially in relationships. Paradoxically, we also need space and quiet, which can cause problems with partners, who might misinterpret it as rejection. We're often socially mature and present a confident exterior that hides a lot of turmoil and insecurity.

There isn't another child that you can watch, compare yourself with and compete against. It's a missing experience. I think that does leave disadvantages in adult life: you feel other people know better how to "do" relationships with peers, how to negotiate, how to be part of a group. But there are pluses too. Time alone helps you become resourceful, develop your imagination and creativity. I think the ability to operate on your own can sometimes give you the impetus to really go for something.

Geoff Allinson, 60

When I was 13 my father died, and what sticks in my mind is how, at his funeral, a neighbour put her hand on my shoulder and said, "You're the man of the house now, Geoff. You've got to look after your mother."

That responsibility weighed on me: I was only a boy. We were very close, as you are when there's just the two of you: but I also felt trapped because, like all teenagers, I wanted to start looking beyond my home to the big wide world.

Three years later Mum married again, and I remember feeling such relief, because now I could live my own life.

Over the following decades I was married and raising my own three children - I always wanted more than one - but there was always this worry in the back of my mind that one day my mother would be on her own again, and I'd be the only person there for her. Then six years ago, my stepfather died.

I was living down south and my mum was in Leeds, so there was a big distance involved and that made things hard. It was very draining, not having anyone else to share it all with; not just the practical stuff, but the worry too. In the end I decided to give up my job to care for her, and I moved her down to live with me.

I'm pleased to think that, in the years ahead, my kids have one another to share the difficulties with. In my experience, that will make a difference.

Anne Parker, 68

I'm single and I've never had children, so as I was an only child I've got no family now. And there are times when you think, it would be nice to have a gorgeous, kind brother or some lovely nieces or nephews who'd come over and help me out or just be around. But that's the most negative I could be about it, really. On the whole I'm pretty contented; I've got a lot of great friends and neighbours, and you don't miss what you've never had.

I don't suppose my parents set out to have a family with only one child in it but the war intervened: my father went off to fight when I was four, at precisely the moment when they might have had a second child. When he came back I do remember saying to both of them that I wanted a sister and it was always maybe, maybe ... But it never happened. I would have welcomed a sibling, though, at that point: I know that.

But there have been lots of advantages to being an only child. I grew up being very good at occupying myself, very self-sufficient, and that's always stood me in good stead.

And a lot of the opportunities for arguments are removed when you're an only child: when my second parent died, for example, the whole issue over inheritance was completely straightforward. I've seen terrible rows between siblings over inheritance, so I was spared all that.

· Being An Only (www.beinganonly.com) is an organisation founded by Ann Richardson as a resource for only children: it runs workshops, social events and conferences.